JP2002014506A - Image forming device and control method for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly respond to a printing request of a user by keeping down lowering of throughput due to detection of speed of movement of an intermediate transfer body and implementation of correction control of the speed of movement of the intermediate transfer body based on the detected result. SOLUTION: This device is characterized in that a detection pattern to detect the speed of movement of the intermediate transfer body is formed on the intermediate transfer belt 119 corresponding to a range between pieces of paper that is a non-printing range during continuous printing, and the speed of movement of the intermediate transfer body is controlled by a controller part 102 by detecting the movement speed detecting pattern formed on the intermediate transfer body by a sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus in which a plurality of image forming stations are juxtaposed and a color image can be formed using an intermediate transfer member which moves an image formed at each image forming station endlessly. The present invention relates to a method for controlling an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, in this type of image forming apparatus,
To form a color image, yellow, magenta,
It has a developing device for developing toner of four colors of cyan and black, and superimposes and transfers the toner image from the developing device of each color to the endless belt once, and again transfers the toner image transferred on the endless belt to a paper. A color image is formed on a sheet by transferring the image onto the sheet.

In this case, a color shift occurs due to a change in the speed of the endless belt, and the quality of a color image is degraded. Hereinafter, detection of a color shift caused by a change in the speed of the endless belt and a correction method thereof will be described.

FIG. 8 is a diagram for explaining an image state formed on an endless belt in this type of image forming apparatus. FIG. 8A shows a state in which color shift does not occur when printing is performed in an ideal state. (B) corresponds to a case where the moving speed of the endless belt changes and an image is formed at a position deviating from an ideal position.

[0005] In addition, if the moving speed of the endless belt changes, there arises a problem that the image writing position from the leading edge of the sheet shifts.

Next, a method for detecting and correcting the moving speed of the endless belt will be described.

FIG. 9 is a flowchart for explaining the control operation for detecting and correcting the moving speed of the endless belt in the conventional image forming apparatus. S301 to S307
Indicates each step.

As shown in FIG. 9, when control for detecting and correcting the moving speed of the endless belt is started in the conventional image forming apparatus, first, in step S301, whether or not continuous printing is currently being executed is determined. If it is determined that continuous printing is not being performed, in step S302, the moving speed detection control of the endless belt is executed, and step S303 is performed.
Then, the rotation speed of the drive motor of the endless belt is reset so that the detected endless belt moving speed becomes a predetermined speed, and the process is terminated. The control for detecting the moving speed of the endless belt will be described later in detail.

When the rotation speed of the motor for driving the endless belt is changed in step S303, the moving speed of the endless belt becomes a predetermined speed so that an image can be formed without color shift. Become.

On the other hand, if it is determined in step S301 that continuous printing is being performed, continuous printing is temporarily suspended as shown in step S304. Then, an endless belt moving speed detection control is executed as shown in step S305, and the endless belt driving motor is driven so that the detected endless belt moving speed becomes a predetermined speed as shown in step S306. Reset the rotation speed of.

Then, in step S307, the continuous printing temporarily suspended in step S303 is restarted.

Next, the control for detecting the moving speed of the endless belt will be described in detail.

FIG. 10 is a flowchart for explaining the operation of detecting the moving speed of the endless belt in the conventional image forming apparatus. In addition, S401 to S406 indicate each step.

FIG. 11 shows an example of an endless belt moving speed detection pattern in a conventional image forming apparatus.

In FIG. 11, reference numeral 501 denotes an endless belt which is driven by a transport motor (not shown). Reference numeral 502 denotes a registration mark detection sensor (registration detection sensor) that detects a color misregistration detection pattern or speed detection patterns 503 and 504 for detecting the moving speed of the endless belt at predetermined positions.

As shown in FIG. 10, when the control for detecting the moving speed of the endless belt is started, step S40 is started.
As shown in FIG. 1, the speed detection patterns 503 and 504 are formed on the endless belt 501.

Next, as shown in step S402, the process waits until the registration detection sensor 502 detects the speed detection pattern 503. When the speed detection pattern 503 is detected by the registration detection sensor 502, step S
As shown at 403, the time count value of the pattern detection time (stored on the internal memory such as the RAM in the controller) is cleared.

Next, as shown in step S404, the process waits until the registration detection sensor 502 detects the speed detection pattern 504, and continues to count the time by the pattern detection time count value while the speed detection pattern is not detected. Then, if the registration detection sensor 502 is detected in step S404, step S406
In, the controller (not shown) calculates the moving speed of the endless belt from the distance between the speed detection patterns 503 and 504 and the time count value counted by the detection time count value, and the process ends. As described above,
The moving speed of the endless belt can be detected and corrected. In addition, the calculated moving speed information of the endless belt is as follows.
It shall be stored on an internal memory such as a RAM in the controller.

[0019]

However, in the conventional image forming apparatus, as described above, even during continuous printing operation due to machine body temperature, ambient temperature and humidity, machine body displacement due to vibration accompanying printing operation, and the like. Since the moving speed of the endless belt changes, it is necessary to execute detection and correction control of the moving speed of the endless belt from time to time even during continuous printing, during which the original printing operation can be performed. Without
There has been a problem that a situation occurs in which it is not possible to quickly respond to a user's color printing request.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus, comprising: By forming a detection pattern for detecting the moving speed of the transfer body, detecting the formed moving speed detection pattern on the intermediate transfer body and controlling the moving speed of the intermediate transfer body, the movement of the intermediate transfer body is controlled. Provided is an image forming apparatus and a control method of the image forming apparatus capable of promptly responding to a user's print request while suppressing a decrease in throughput due to speed detection and execution of movement speed correction control of the intermediate transfer body based on the detection result. It is.

[0021]

According to a first aspect of the present invention, a plurality of image forming stations are arranged side by side, and a color image is formed using an intermediate transfer member which moves an image formed at each image forming station endlessly. A driving unit (FIG. 1) for transporting and driving the intermediate transfer body.
And the speed of the intermediate transfer body conveyed by the driving unit in a region corresponding to a sheet interval set for a recording medium conveyed during continuous printing. A pattern forming means for forming a speed detection pattern for detection (corresponding to an image forming station for each color juxtaposed as shown in FIG. 1), and the speed formed on the intermediate transfer body by the pattern forming means A pattern detecting means (corresponding to the registration detection sensor 502 shown in FIG. 2) for detecting a detection pattern, and a calculating means (FIG. 1) for calculating a moving speed value of the intermediate transfer member based on a pattern detection result by the pattern detecting means. And a driving state of the driving unit based on the calculation result of the calculation unit to control the transport speed of the intermediate transfer body. Control means for those having a (corresponding to the controller unit 102 shown in FIG. 1).

According to a second aspect of the present invention, the intermediate transfer member is an endless belt (intermediate transfer belt 119 shown in FIG. 1).
).

According to a third aspect of the present invention, the control means detects a speed detection pattern formed on the intermediate transfer body a plurality of times by the pattern detection means, and the calculation means calculates based on the detection result. The obtained average moving speed value is processed as the moving speed value of the intermediate transfer member.

According to a fourth aspect of the present invention, the control means includes a first setting means for variably setting a paper interval length of the recording medium to be longer than a normal paper interval every time a predetermined condition is satisfied. Detecting a speed detection pattern formed on a paper interval set variably longer by the first setting means a plurality of times;
The moving speed average value calculated by the calculating means based on the detection result is processed as the moving speed value of the intermediate transfer body.

According to a fifth aspect of the present invention, the driving means includes a driving roller, and the control means sets the paper interval length of the recording medium to be equal to or greater than the circumferential length of the driving roller every time a predetermined condition is satisfied. The speed formed between the sheets variably set to be equal to or greater than the circumference of the driving roller by the second setting means. The detection pattern is detected a plurality of times, and the moving speed average value calculated by the calculating means based on the detection result is processed as the moving speed value of the intermediate transfer body.

According to a sixth aspect of the present invention, the control means variably sets a paper interval length of the recording medium to be longer than a normal paper interval every time a predetermined number of recording media are printed continuously. A speed detection pattern formed between the papers set to be longer and variably set by the third setting means is detected a plurality of times, and the third setting means (corresponding to the controller unit 102 shown in FIG. The moving speed average value calculated by the calculating means based on the detection result is processed as the moving speed value of the intermediate transfer body.

According to a seventh aspect of the present invention, there is provided an environmental condition detecting means (corresponding to the condition detecting sensor S shown in FIG. 1) for detecting the environmental condition of the image forming means, and the control means comprises: A fourth step of variably setting the paper interval length of the recording medium to be longer than the normal paper interval when the measurement result of the detection means changes by a predetermined value or more from the previous measurement of the intermediate transfer body moving speed;
Setting means (corresponding to the controller unit 102 shown in FIG. 1)
Detecting a speed detection pattern formed between sheets variably set longer by the fourth setting means a plurality of times,
The moving speed average value calculated by the calculating means based on the detection result is processed as the moving speed value of the intermediate transfer body.

In an eighth aspect according to the present invention, the environmental condition detecting means is a humidity sensor or a temperature sensor.

In a ninth aspect according to the present invention, when the control means changes a predetermined value or more from the previous measurement of the intermediate transfer body moving speed, the control unit sets the sheet interval length of the recording medium to be longer than the normal sheet interval. A fifth setting means (corresponding to the controller unit 102 shown in FIG. 1) for variably setting a longer time is provided, and the speed detection pattern formed between the sheets variably set longer by the fifth setting means is set a plurality of times. The intermediate transfer member is detected, and the moving speed average value calculated by the calculating means based on the detection result is processed as the moving speed value of the intermediate transfer body.

In a tenth aspect according to the present invention, the driving means includes a driving roller, and the control means controls a driving state of the driving roller based on a calculation result by the calculation means to control the intermediate transfer. It controls the body transport speed.

According to an eleventh aspect of the present invention, the intermediate transfer member is formed such that each color image is formed by being transported in a plane along a plurality of image stations and passing therethrough.

According to a twelfth aspect of the present invention, a plurality of image forming stations are arranged side by side, and a color image is formed using an intermediate transfer member which is driven endlessly by driving the images formed by the respective image forming stations. A method for controlling an image forming apparatus capable of forming an image, wherein the intermediate transfer body conveyed by the driving unit to an area corresponding to a sheet interval set for a recording medium conveyed during continuous printing Pattern forming step of forming a speed detection pattern for detecting the speed of the image (step S702 shown in FIG. 4), and a pattern detecting step of detecting the speed detection pattern formed on the intermediate transfer body by the pattern forming step (FIG. 4
(Step S703 shown in FIG. 4) and a calculation step (Step S70 shown in FIG. 4) for calculating the moving speed value of the intermediate transfer member based on the pattern detection result in the pattern detection step.
7) and a control step of controlling the driving state of the drive unit based on the calculation result of the calculation step to control the transport speed of the intermediate transfer body (steps S603 and S603 shown in FIG. 3).
607).

According to a thirteenth aspect of the present invention, the intermediate transfer member is an endless belt.

According to a fourteenth aspect of the present invention, in the control step, the speed detection pattern formed on the intermediate transfer body in the pattern detection step is detected a plurality of times, and the calculation step (FIG. Step S812 shown in FIG. 5)
Is processed as the moving speed value of the intermediate transfer member with the calculated moving speed average value.

In a fifteenth aspect of the present invention, the control means variably sets a paper interval length of the recording medium to be longer than a normal paper interval every time a predetermined condition is satisfied. Step S904 shown in FIG. 6) is performed, and a speed detection pattern formed between sheets which is set variably longer in the first setting step is detected a plurality of times, and the calculation step (FIG. 5) is performed based on the detection result. In step S812), the average moving speed calculated is processed as the moving speed of the intermediate transfer member.

According to a sixteenth aspect of the present invention, the driving means includes a driving roller, and the control step sets the paper interval length of the recording medium to be equal to or greater than the peripheral length of the driving roller every time a predetermined condition is satisfied. A second setting step of variably setting (step S904 shown in FIG. 6) a plurality of speed detection patterns formed between sheets variably set to be equal to or longer than the circumference of the driving roller by the second setting step; The intermediate transfer member is detected as the moving speed value of the intermediate transfer member using the moving speed average value calculated in the calculating step (step S812 shown in FIG. 5) based on the detection result.

According to a seventeenth aspect of the present invention, in the control step, each time a predetermined number of recording media are continuously printed, the paper interval length of the recording media is variably set to be longer than a normal paper interval. A third setting step (step S904 shown in FIG. 6) is performed to detect a speed detection pattern formed between sheets that is variably set longer in the third setting step a plurality of times. Based on the calculation process (step S shown in FIG. 5)
812) is processed as the moving speed value of the intermediate transfer body using the calculated moving speed average value.

An eighteenth invention according to the present invention has an environmental state detecting step (not shown) for detecting an environmental state of the image forming means, and the control step comprises the steps of: A fourth setting step (step S904 shown in FIG. 6) of variably setting the paper interval length of the recording medium to be longer than the normal paper interval when the intermediate transfer body moving speed has changed by a predetermined value or more from the measurement. Then, the speed detection pattern formed between the paper sheets which has been variably set longer in the fourth setting step is detected a plurality of times, and the movement calculated in the calculation step (step S812 shown in FIG. 5) based on the detection result. The speed average value is processed as the moving speed value of the intermediate transfer body.

According to a nineteenth aspect of the present invention, in the environmental condition detecting step, humidity or temperature is detected.

According to a twentieth aspect of the present invention, in the control step, when the intermediate transfer body moving speed has changed by a predetermined value or more from the previous measurement, the paper interval length of the recording medium is made longer than the normal paper interval. A fifth setting step (step S904 shown in FIG. 6) of variably setting a longer time, and detecting a speed detection pattern formed between sheets longer variably set by the fifth setting step a plurality of times; Based on the detection result, the moving speed average value calculated in the calculating step (step S812 shown in FIG. 5) is processed as the moving speed value of the intermediate transfer body.

According to a twenty-first aspect of the present invention, the driving means includes a driving roller, and the control step controls the driving state of the driving roller based on a calculation result by the calculation means to control the intermediate transfer. It controls the body transport speed.

According to a twenty-second aspect of the present invention, the intermediate transfer member is transported in a plane along a plurality of image stations and passes therethrough, whereby each color image is formed.

[0043]

[First Embodiment] FIG. 1 is a sectional view showing an example of an image forming apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numeral 101 denotes an engine control unit which controls the entire image forming apparatus. A controller unit 102 includes a CPU, a RAM, a ROM, and the like, and outputs image information by executing a control program stored in the ROM.

Reference numeral 103 denotes a yellow laser beam scanning system having a yellow rotating polygon mirror 125, which scans a laser beam deflected by the yellow rotating polygon mirror 125 on a yellow photosensitive drum 105 to form an electrostatic image. Form a latent image. Reference numeral 106 denotes a yellow developing unit,
The electrostatic latent image formed on 5 is developed into a visible image with yellow toner.

Reference numeral 107 denotes a magenta laser beam scanning system, which includes a magenta rotary polygon mirror 126, and scans a laser beam deflected by the magenta rotary polygon mirror 126 onto a magenta photosensitive drum 113 to form an electrostatic image. Form a latent image. Reference numeral 116 denotes a magenta developing section,
3 is developed into a visible image with magenta toner.

Reference numeral 108 denotes a cyan laser beam scanning system which includes a cyan rotary polygon mirror 127, and scans a laser beam deflected by the magenta rotary polygon mirror 127 onto a cyan photosensitive drum 114 to form an electrostatic image. Form a latent image. A cyan developing unit 117 develops the electrostatic latent image formed on the photosensitive drum 114 into a visible image using cyan toner.

A black laser beam scanning system 109 is provided with a black rotating polygon mirror 128, and scans the black photosensitive drum 115 with a laser beam deflected by the black rotating polygon mirror 128 to form an electrostatic image. Form a latent image. Reference numeral 118 denotes a black developing unit which is a photosensitive drum 11
5 is developed into a visible image with black toner.

Reference numeral 119 denotes an intermediate transfer belt which rotates in a direction indicated by an arrow at a predetermined speed based on a rotational force transmitted by a drive motor (not shown).
4 and 115, the visible images formed thereon are sequentially primary-transferred.

Reference numeral 129 denotes a yellow primary transfer portion, which primarily transfers a yellow visible image onto the intermediate transfer belt 119. Reference numeral 130 denotes a magenta primary transfer unit which primarily transfers a magenta visible image onto the intermediate transfer belt 119. 131
Is a primary transfer section for cyan, which primarily transfers a cyan visible image onto the intermediate transfer belt 119. 132 is black 1
At the next transfer section, the black visible image is transferred to the intermediate transfer belt 11.
9 is primarily transferred.

Reference numeral 120 denotes a paper feed tray. When a manually fed paper sheet is set, the paper is conveyed by a paper feed roller 121 at a predetermined timing.

Reference numeral 122 denotes a transfer roller, which is an intermediate transfer belt 1
19 is secondarily transferred to the recording paper. A fixing device 123 fixes the toner image transferred onto the recording paper by applying heat and pressure, and is conveyed and stacked on a paper discharge tray 124.

Reference numeral 133 denotes a paper feed cassette which stores recording paper of a fixed size. A reversing unit 134 switches the transport path by driving a flapper or the like (not shown), and pulls in the recording paper on which the fixing process is completed and temporarily stops the recording paper.
Reference numeral 138 denotes a paper storage detection sensor which detects the presence or absence of recording paper taken in the reversing unit 134 and notifies the controller of the detection result.

Reference numeral 135 denotes a paper discharge tray which discharges the recording paper on which the fixing process has been completed in the order of pages with the recording surface lying down (face down state). A paper discharge detection sensor 137 detects the passing state of the recording paper discharged and conveyed, and notifies the controller of the detection result.

S is a state detection sensor which detects the temperature or humidity in the machine and notifies the controller 102 of the detected temperature or humidity.

In the image forming apparatus configured as described above, a plurality of image forming stations are juxtaposed, and a color image can be formed using the intermediate transfer belt 119 that moves the image formed at each image forming station endlessly. Fig. 1
The image forming apparatus shown in (1) includes a driving roller, which is a driving unit that conveys and drives the intermediate transfer belt 119 at a predetermined speed, to which a rotational force is transmitted by a driving motor (not shown). A speed detection pattern for detecting the speed of the intermediate transfer body conveyed by the driving roller 1000 is formed in an area corresponding to the inter-sheet interval set by the printer, and the speed detection pattern formed on the intermediate transfer belt 119 is formed. After the pattern (see FIG. 2) is detected and the moving speed value of the intermediate transfer belt 119 is calculated based on the detection result, the controller 102 controls the driving state of the driving roller based on the calculation result, thereby controlling the intermediate transfer belt 119. Belt 1
19 is controlled.

At this time, the controller unit 102 detects the speed detection pattern formed on the intermediate transfer belt 119 a plurality of times by the registration detection sensor 502, and uses the average moving speed calculated based on the detection result as the intermediate transfer belt 119.
Is processed.

Further, the controller unit 102 variably sets the paper interval length of the recording medium to be longer than the normal paper interval each time a predetermined condition is met, and is formed between the variably set papers. The speed detection pattern is detected a plurality of times, and the moving speed average value calculated based on the detection result is processed as the moving speed value of the intermediate transfer belt 119.

Further, the controller unit 102 variably sets the paper interval length of the recording medium to be equal to or longer than the circumference of the driving roller 1000 every time a predetermined condition is satisfied.
A speed detection pattern formed between sheets variably set to a circumference of 0 or more is detected a plurality of times, and a moving speed average value calculated based on the detection result is processed as a moving speed value of the intermediate transfer belt 119.

Further, the controller unit 102 variably sets the paper interval length of the recording medium to be longer than the normal paper interval each time a predetermined number of recording media are continuously printed, and variably sets the paper interval length. The speed detection pattern formed on the paper interval is detected a plurality of times, and the moving speed average value calculated based on the detection result is processed as the moving speed value of the intermediate transfer belt 119.

The controller 102 has a state detecting sensor S as an environmental state detecting means for detecting an environmental state of the image forming means. , The paper interval length of the recording medium is variably set to be longer than the normal paper interval, and a speed detection pattern formed between the variably set papers is detected a plurality of times. The moving speed average value calculated by the calculating means based on the detection result is processed as the moving speed value of the intermediate transfer belt 119.

It is assumed that the state detection sensor S is a humidity sensor or a temperature sensor.

The controller unit 102 variably sets the paper interval length of the recording medium to be longer than the normal paper interval when the intermediate transfer body moving speed has changed by a predetermined value or more from the previous measurement, and the controller unit 102 variably changes the paper interval length. The speed detecting pattern formed on the set sheet interval is detected a plurality of times, and the moving speed average value calculated by the calculating means based on the detection result is processed as the moving speed value of the intermediate transfer belt 119.

The controller 102 controls the driving state of the driving roller 1000 to control the intermediate transfer belt 119.
Is controlled.

Further, it is assumed that the intermediate transfer body is transported in a plane along a plurality of image stations and passes therethrough, thereby forming an image of each color.

FIG. 2 shows the intermediate transfer belt 11 shown in FIG.
FIG. 9 is a diagram illustrating an example of a speed detection pattern formed between papers on a ninth embodiment, and a hatched portion is an image area formed during continuous image formation.

In FIG. 2, reference numeral 502 denotes a registration mark detection sensor (registration detection sensor) which detects a color misregistration detection pattern or speed detection patterns 503 and 504 for detecting the moving speed of the endless belt at predetermined positions.

FIG. 3 is a flowchart showing an example of a first image forming processing procedure in the image forming apparatus according to the present invention. The moving speed of the endless intermediate transfer belt 119 shown in FIG. 1 is detected and corrected. Corresponds to the control procedure. In addition,
S601 to S605 indicate each step.

First, when the control for detecting and correcting the moving speed of the endless belt in the image forming apparatus is started, as shown in step S601, it is determined whether or not continuous printing is being performed. As in the conventional case,
0 is executed (step S602), and the endless intermediate transfer belt 119 is moved so that the detected endless belt moving speed becomes a predetermined speed as shown in step S603. Reset the rotation speed of the drive motor.

On the other hand, if it is determined in step S601 that continuous printing is being executed, belt movement speed detection control during continuous printing is executed as shown in step S604, and in step S605, the endless intermediate transfer belt 11 is detected.
The rotation speed of the drive motor is changed so that the movement speed of Step 9 becomes a predetermined speed, and the process ends. The control for detecting the moving speed of the endless intermediate transfer belt 119 during continuous printing will be described later in detail.

When the rotation speed of the drive motor is changed during continuous printing, the influence of the change in motor rotation speed on the image being printed is reduced, so that the image being printed is not affected. The rotational speed of the drive motor is changed.

Next, the control for detecting the moving speed of the endless intermediate transfer belt 119 during continuous printing will be described in detail.

FIG. 4 is a flow chart showing an example of the second image forming processing procedure in the image forming apparatus according to the present invention, which corresponds to the moving speed detection control procedure of the endless intermediate transfer belt 119 shown in FIG. I do. Note that S701 to S701
707 indicates each step.

As shown in FIG. 4, when the control for detecting the moving speed of the endless belt is started, step S701 is performed.
As shown in (1), the timing between the sheets, which is the non-printing area, on the black photosensitive drum 115 is waited. Then, at the timing between the papers on the black photosensitive drum 115, the speed detection patterns 503 and 504 for detecting the moving speed of the endless intermediate transfer belt are changed to the black photosensitive drum 115 as shown in step S702. From the endless intermediate transfer belt 119.

Next, as shown in step S703, the process waits until the registration detection sensor 502 detects the speed detection pattern 503. When the speed detection pattern 503 is detected by the registration detection sensor 502, step S
As shown in 704, the time count value of the pattern detection time (stored in the memory in the controller unit 102) is cleared.

Next, the process waits until the registration detection sensor 502 detects the detection pattern 504 as shown in step S705, and while the detection pattern is not detected, the time is counted by the pattern detection time count value as shown in step S706. Keep counting.

On the other hand, if it is determined in step S705 that the registration detection sensor 502 has been detected, the speed detection pattern 50 for detecting the endless belt moving speed is used.
The controller 102 calculates the moving speed of the endless intermediate transfer belt 119 from the distance between the distances 3 and 504 and the time count value counted by the detection time count value.
The process ends.

As described above, the belt movement speed detection pattern is formed on the controller section 102 between the papers which are non-printing areas, and the formed belt movement speed detection pattern on the controller section 102 is detected by the registration detection sensor 502. And the moving speed of the controller unit 102 is detected.
It is possible to provide a color image forming apparatus capable of responding to a user's print request more quickly than before, while suppressing a decrease in throughput due to execution of control for detecting the moving speed of the controller unit 102.

In the above-described embodiment, for example, the speed detection pattern for detecting the endless belt moving speed in the black photosensitive drum 115 is set to the intermediate transfer belt 1.
19, it is possible to form various patterns based on the purpose of the present invention. For example, a pattern may be formed by a photosensitive drum of another color. It is not excluded from the scope of the invention.

[Second Embodiment] In the first embodiment,
A belt movement speed detection pattern is formed on the intermediate transfer belt 119 between the non-printing areas, and the formed belt movement speed detection pattern on the formed intermediate transfer belt 119 is detected using the registration detection sensor 502 to perform intermediate transfer. A case has been described in which the control for detecting the moving speed of the belt 119 is performed. However, in order to make the detected moving speed of the intermediate transfer belt 119 an average value instead of a local value, the intermediate transfer belt having a plurality of endless shapes is used. The control unit 102 may be configured to detect the moving speed of the intermediate transfer belt 119, calculate the average value thereof, and make the average speed of the intermediate transfer belt 119 as the moving speed. Hereinafter, the embodiment will be described. In addition,
Detects the moving speed of the endless belt in the image forming apparatus.
The operation of the control for correction performs the same control as in the first embodiment.

FIG. 5 is a flowchart showing an example of a third image forming process procedure in the image forming apparatus according to the present invention. The procedure for detecting the moving speed of the endless intermediate transfer belt 119 shown in FIG. (Including control for detecting the average value of the moving speed of the endless belt during printing). S801 to S807 indicate each step.

As shown in FIG. 5, when the control for detecting the average value of the moving speed of the endless intermediate transfer belt 119 is started, the count value of the number of times the moving speed is sampled as shown in step S801. (Controller unit 10
(Stored in the memory in 2).

Next, in step S802, it is determined whether or not the count value of the number of times of sampling has reached a predetermined value.
If it is determined that the sampling number count value has not reached the predetermined value, the control is shifted to step S803,
The timing between the papers, which is the non-print area, on the black photosensitive drum 115 is waited. When the timing between the papers on the black photosensitive drum 115 is reached, the speed detection patterns 503 and 504 for detecting the endless belt moving speed are changed from the black photosensitive drum 115 to the endless belt as shown in step S804. Form on top.

Next, as shown in step S805, the process waits until the registration detection sensor 502 detects the speed detection pattern 503. When the speed detection pattern 503 is detected by the registration detection sensor 502, step S
As shown at 806, the time count value of the pattern detection time is cleared.

Next, as shown in step S807, the process waits until the speed detection pattern 504 is detected by the registration detection sensor 502, and while the speed detection pattern 504 is not detected, the pattern detection time count is executed as shown in step S808. Continue counting time by value. If the registration detection sensor 502 detects the speed detection pattern 504 in step S807, the process proceeds to step S8.
In step 09, the value of the moving speed of the endless belt at the time of measurement is calculated from the distance between the speed detection patterns 503 and 504 and the time count value counted by the detection time count value.

In step S810, the value of the moving speed of the endless belt calculated in step S809 is temporarily saved in the memory.

Here, the memory is secured by the number of times of sampling, and every time the moving speed of the endless intermediate transfer belt 119 is measured, the memory is calculated in another memory area in the memory of the controller unit 102 in step S809. The value of the moving speed of the endless belt is sequentially stored.

Next, the count value of the number of times of sampling is incremented as the number of times the moving speed of the endless intermediate transfer belt 119 has been measured in step S811, and step S811 is executed.
The control of returning to 802 is repeated until the count value of the number of times of sampling reaches a predetermined value.

Finally, if it is determined in step S802 that the count value of the number of times of sampling has reached the predetermined value, as shown in step S812, the moving speed of the endless belt temporarily evacuated in step S810. The controller 102 calculates a value obtained by dividing the sum of the values by the number of times of sampling, and calculates the average value of the endless belt moving speed as the moving speed of the endless intermediate transfer belt 119 during continuous printing.

As described above, the belt movement speed detection patterns are sequentially formed on the endless belt between the papers that are the non-printing areas, and the belt movement speed detection patterns on the formed endless intermediate transfer belt 119 are registered. Since the moving speed of the endless intermediate transfer belt 119 is detected by the detection sensor 502, a decrease in throughput due to the execution of control for detecting the moving speed of the endless intermediate transfer belt 119 is suppressed, and the It is possible to provide a color image forming apparatus capable of promptly responding to the printing request of (1).

Further, the intermediate transfer belt 11 having a plurality of endless
9, the average value is taken as the moving speed of the endless belt, so that the average moving speed of the detected endless belt can be detected. Compared to calculating the moving speed of the belt, it is possible to detect the endless belt moving speed in which the speed variation due to the speed unevenness is suppressed.

In the above-described embodiment, the endless belt moving speed detection pattern is formed on the endless belt in the black photosensitive drum. However, this is because the pattern is formed by the photosensitive drums of other colors. It does not matter. Further, in the above-described embodiment, each time the belt moving speed is measured, the belt is temporarily evacuated to another memory area. However, the measured value is added to a certain memory area, and finally divided by the number of times of sampling. It is possible to make various modifications based on the gist of the present invention, for example, even if the average value is calculated by the following formula, and these are not excluded from the scope of the present invention.

[Third Embodiment] In the first and second embodiments, the movement speed detection pattern is formed on the endless belt by controlling the length between the papers, which is the non-printing area. By detecting the belt moving speed detection pattern on the endless intermediate transfer belt 119 by the registration detection sensor 502 and detecting the moving speed of the endless intermediate transfer belt 119, a speed having a period longer than the normal sheet-to-paper distance is detected. The control for detecting the moving speed of the endless intermediate transfer belt 119 by canceling the unevenness may be performed. Hereinafter, the embodiment will be described.

FIG. 6 is a flowchart showing an example of the fourth image forming processing procedure in the image forming apparatus according to the present invention. The control procedure for detecting and correcting the moving speed of the endless intermediate transfer belt 119 (for example, FIG. In the image forming apparatus having a configuration in which the distance corresponding to one rotation of the belt driving shaft is longer than the normal paper interval shown in FIG. 2, the rotation unevenness of the belt driving shaft driving the endless intermediate transfer belt 119 is canceled. (Including a control procedure for detecting the belt moving speed). In addition, S901 to S907 indicate each step.

First, as shown in step S901, it is determined whether or not continuous printing is being performed. If it is determined that continuous printing is not being performed, as in step S902, the endless process described in FIG. Intermediate transfer belt 1
The moving speed detection control of 19 is executed, and the rotation speed of the drive motor of the endless belt is reset so that the detected endless belt moving speed becomes a predetermined speed as shown in step S903.

On the other hand, if it is determined in step S901 that continuous printing is being performed, continuous printing is continued with the sheet interval wider than the normal sheet interval as shown in step S904.

Here, for example, when it is desired to detect the belt moving speed by canceling the rotation unevenness of the belt driving shaft, the sheet interval is extended to a distance equal to or more than one rotation of the belt driving shaft.

Then, as shown in step S905, control for detecting the belt moving speed during continuous printing is executed, and as shown in step S906, the driving motor is controlled so that the moving speed of the endless intermediate transfer belt 119 becomes a predetermined speed. Change the rotation speed.

Here, in the control for detecting the moving speed of the endless intermediate transfer belt 119 during the continuous printing in step S905, for example, when it is desired to detect the belt moving speed by canceling the rotation unevenness of the belt drive shaft, the endless belt is required. If the same control as that described in the first embodiment is performed with the line intervals of the endless belt speed detection pattern formed on the belt-like intermediate transfer belt 119 separated by a distance corresponding to one rotation of the belt drive shaft, good.

When the rotational speed of the drive motor is changed during continuous printing, the influence of the change in the motor rotational speed on the image being printed is reduced so that the image being printed is not affected. The rotational speed of the drive motor is changed.

Finally, as shown in step S907, the setting is changed so that the length between the sheets returns to the original length, and the process ends.

As described above, the moving speed detection pattern is formed on the endless intermediate transfer belt 119 by controlling the length between the papers, which is the non-printing area, and the formed endless intermediate transfer belt 119 is formed. By detecting the upper belt moving speed detection pattern by the detecting means and detecting the moving speed of the endless intermediate transfer belt 119, speed unevenness having a cycle longer than the normal sheet-to-paper distance is canceled, and the endless intermediate transfer belt 119 is canceled. The moving speed of the transfer belt 119 can be detected.

Further, even in the case of detecting the belt moving speed with a belt moving speed detecting pattern longer than the sheet interval in order to cancel the speed unevenness in a cycle longer than the normal sheet interval, continuous printing is performed. The belt moving speed can be detected without interruption.

In the above embodiment, the case where the belt movement speed is detected by canceling the rotation unevenness of the belt driving roller has been described. However, in order to detect the belt movement speed by canceling the speed unevenness of another cycle. It is sufficient that continuous printing is continued with a paper interval longer than the cycle and a belt movement speed detection pattern is formed at the same interval as the cycle, and various modifications can be made based on the spirit of the present invention. Yes, and they are not excluded from the scope of the present invention.

According to each of the above-described embodiments, the control for detecting the moving speed of the endless belt between the papers, which is the non-printing area, is performed during the continuous printing, thereby detecting the moving speed of the endless belt and the detection thereof. It is possible to provide an image forming apparatus that can quickly respond to a user's print request while suppressing a decrease in throughput due to execution of correction control based on the result.

Hereinafter, the structure of a data processing program that can be read by an image processing system to which the image forming apparatus according to the present invention can be applied will be described with reference to a memory map shown in FIG.

FIG. 7 is a diagram illustrating a memory map of a storage medium storing various data processing programs that can be read by an image processing system to which the image forming apparatus according to the present invention can be applied.

Although not shown, information for managing a group of programs stored in the storage medium, such as version information and a creator, is also stored, and information dependent on the OS or the like on the program reading side, such as a program, An icon or the like for identification display may also be stored.

Further, data dependent on various programs is also managed in the directory. In addition, a program for installing various programs on a computer or a program for decompressing a program to be installed when the program to be installed is compressed may be stored.

The functions shown in FIGS. 3 to 6 in this embodiment may be performed by a host computer by a program installed from the outside. And in that case, CD-ROM, flash memory, FD
The present invention is applicable even when a group of information including a program is supplied to an output device from a storage medium such as the above or from an external storage medium via a network.

As described above, the storage medium storing the program codes of the software for realizing the functions of the above-described embodiments is supplied to the system or the apparatus, and the computer (or CPU or MP) of the system or the apparatus is supplied.
It goes without saying that the object of the present invention is also achieved when U) reads and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk,
D-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, EEPROM, etc. can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) And the like perform part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, The CPU provided in the function expansion board or function expansion unit performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

[0116]

As described above, the first embodiment according to the present invention is described.
According to the twenty-second aspect, during continuous printing, a detection pattern for detecting the moving speed of the intermediate transfer body is formed on the intermediate transfer body corresponding to the inter-sheet area which is a non-print area, and the formation pattern is formed. Detecting the moving speed detection pattern on the intermediate transfer body and controlling the moving speed of the intermediate transfer body to detect the moving speed of the intermediate transfer body and execute the movement speed correction control of the intermediate transfer body based on the detection result. Therefore, it is possible to respond to a user's print request quickly while suppressing a decrease in throughput due to the above.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram illustrating an example of an image forming apparatus according to a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing an example of a speed detection pattern formed on a space between sheets on the intermediate transfer belt shown in FIG. 1;

FIG. 3 is a flowchart illustrating an example of a first image forming processing procedure in the image forming apparatus according to the present invention.

FIG. 4 is a flowchart illustrating an example of a second image forming processing procedure in the image forming apparatus according to the present invention.

FIG. 5 is a flowchart illustrating an example of a third image forming processing procedure in the image forming apparatus according to the present invention.

FIG. 6 is a flowchart illustrating an example of a fourth image forming processing procedure in the image forming apparatus according to the present invention.

FIG. 7 is a diagram illustrating a memory map of a storage medium that stores various data processing programs that can be read by an image processing system to which the image forming apparatus according to the present invention can be applied.

FIG. 8 is a diagram for explaining an image state formed on an endless belt in this type of image forming apparatus.

FIG. 9 is a flowchart illustrating a control operation for detecting and correcting the moving speed of the endless belt in the conventional image forming apparatus.

FIG. 10 is a flowchart illustrating an operation of detecting a moving speed of an endless belt in a conventional image forming apparatus.

FIG. 11 is a diagram illustrating an example of an endless belt moving speed detection pattern in a conventional image forming apparatus.

[Explanation of symbols]

 Reference Signs List 101 engine control unit 102 controller unit 105, 113 to 115 photoconductor drum 119 intermediate transfer belt 1000 drive roller

Claims (22)

[Claims] 1. An image forming apparatus capable of forming a color image by using a plurality of image forming stations arranged side by side and an intermediate transfer member that moves an image formed at each image forming station endlessly, wherein the intermediate transfer is performed. A drive unit for driving the body to be transported, and detecting a speed of the intermediate transfer body transported by the drive unit in an area corresponding to a sheet interval set for a recording medium transported during continuous printing. Pattern forming means for forming a speed detection pattern for, pattern detection means for detecting the speed detection pattern formed on the intermediate transfer body by the pattern forming means, based on a pattern detection result by the pattern detection means, Calculating means for calculating a moving speed value of the intermediate transfer member; controlling a driving state of the driving means based on a calculation result by the calculating means; Image forming apparatus characterized by and a control means for controlling the conveying speed of the intermediate transfer body. 2. The image forming apparatus according to claim 1, wherein the intermediate transfer member is an endless belt. 3. The control means detects a speed detection pattern formed on the intermediate transfer body a plurality of times by the pattern detection means, and obtains the intermediate speed average value calculated by the calculation means based on the detection result. The image forming apparatus according to claim 1, wherein the processing is performed as a moving speed value of the transfer body. 4. The control unit includes a first setting unit that variably sets a paper interval length of a recording medium to be longer than a normal paper interval every time a predetermined condition is satisfied. Means for detecting a speed detection pattern formed on a sheet interval variably set longer by a plurality of times, and processing the moving speed average value calculated by the calculating means based on the detection result as a moving speed value of the intermediate transfer body. The image forming apparatus according to claim 1, wherein: 5. The second setting, wherein the driving means includes a driving roller, and wherein the control means variably sets a paper interval length of a recording medium to be equal to or greater than a circumferential length of the driving roller each time a predetermined condition is met. Means for detecting a speed detection pattern formed between sheets variably set to be equal to or longer than the circumference of the drive roller by the second setting means a plurality of times, and the calculating means calculates based on the detection result 2. The image forming apparatus according to claim 1, wherein the moving speed average value is processed as the moving speed value of the intermediate transfer body. 6. The control means has a third setting means for variably setting a paper interval length of the recording medium to be longer than a normal paper interval each time a predetermined number of recording media are continuously printed. The speed detecting pattern formed between the papers set to be longer and variably set by the third setting means is detected a plurality of times, and the moving speed average calculated by the calculating means based on the detection result is used as the intermediate transfer member. 2. The image forming apparatus according to claim 1, wherein the processing is performed as a moving speed value. 7. An environmental condition detecting means for detecting an environmental condition of the image forming means, wherein the control means determines that a measurement result of the environmental condition detecting means is equal to or more than a predetermined value from a previous measurement of the intermediate transfer body moving speed. A fourth setting unit configured to variably set a paper interval length of the recording medium to be longer than a normal paper interval when the recording medium is changed, and to form a paper interval length variably set by the fourth setting unit; 2. The image forming apparatus according to claim 1, wherein the detected speed detection pattern is detected a plurality of times, and the moving speed average value calculated by the calculating means based on the detection result is processed as the moving speed value of the intermediate transfer body. apparatus. 8. An image forming apparatus according to claim 7, wherein said environmental condition detecting means is a humidity sensor or a temperature sensor. 9. The fifth control means for variably setting a paper interval length of the recording medium to be longer than a normal paper interval when a change of a predetermined value or more has occurred since the previous measurement of the intermediate transfer body moving speed. Setting means, detecting a speed detection pattern formed between sheets variably set longer by the fifth setting means a plurality of times, and calculating a moving speed average value calculated by the calculating means based on the detection result. The image forming apparatus according to claim 1, wherein the processing is performed as a moving speed value of the intermediate transfer body. 10. The driving unit includes a driving roller, and the control unit controls a driving state of the driving roller based on a calculation result of the calculation unit to control a conveyance speed of the intermediate transfer body. Claim 6, characterized in that:
An image forming apparatus according to any one of claims 7 and 9. 11. The image forming apparatus according to claim 1, wherein the intermediate transfer body is formed such that each color image is formed by being transported in a plane along a plurality of image stations and passing therethrough.
0. The image forming apparatus according to claim 1, wherein 12. An image forming apparatus in which a plurality of image forming stations are juxtaposed, and an image formed in each image forming station is driven by a driving unit to form a color image by using an intermediate transfer body that moves endlessly. A control method, comprising: a speed for detecting a speed of the intermediate transfer body conveyed by the driving unit with respect to an area corresponding to a sheet interval set for a recording medium conveyed during continuous printing. A pattern forming step of forming a detection pattern; a pattern detecting step of detecting the speed detection pattern formed on the intermediate transfer body by the pattern forming step; and the intermediate transfer based on a pattern detection result of the pattern detecting step. A calculating step of calculating a moving speed value of the body, and controlling a driving state of the driving unit based on a calculation result of the calculating step, Method of controlling an image forming apparatus characterized by and a control step of controlling the conveying speed between the transfer member. 13. The method according to claim 12, wherein the intermediate transfer member is an endless belt. 14. The control step detects a speed detection pattern formed on the intermediate transfer body a plurality of times by the pattern detection step, and uses the moving speed average value calculated by the calculation step based on the detection result to calculate the intermediate speed. 13. The method according to claim 12, wherein the processing is performed as a transfer speed value of the transfer body. 15. The method according to claim 15, wherein the control unit includes a first setting step of variably setting a paper interval length of the recording medium to be longer than a normal paper interval every time a predetermined condition is satisfied; A speed detection pattern formed between sheets which is variably set longer in a process is detected a plurality of times, and a moving speed average value calculated by the calculation process based on the detection result is processed as a moving speed value of the intermediate transfer body. The control method for an image forming apparatus according to claim 12, wherein: 16. The driving unit includes a driving roller, wherein the control step variably sets a paper interval length of a recording medium to be equal to or greater than a peripheral length of the driving roller every time a predetermined condition is met. A speed detection pattern formed on a sheet interval variably set to be equal to or longer than the circumference of the driving roller in the second setting step, and the calculation step calculates based on the detection result. 13. The method according to claim 12, wherein the processing is performed as the moving speed value of the intermediate transfer body with the obtained moving speed average value. 17. The control step includes a third setting step of variably setting a paper interval length of the recording medium to be longer than a normal paper interval every time a predetermined number of recording media are continuously printed. The speed detecting pattern formed between the paper sheets which is set variably longer in the third setting step is detected a plurality of times, and the moving speed average calculated in the calculating step based on the detection result is used as the intermediate transfer member. The method according to claim 12, wherein the processing is performed as a moving speed value. 18. An environmental state detecting step of detecting an environmental state of the image forming means, wherein the control step determines that a measurement result of the environmental state detecting step is equal to or more than a predetermined value from a previous measurement of the intermediate transfer body moving speed. A fourth setting step of variably setting the paper interval length of the recording medium to be longer than a normal paper interval when the recording medium is changed; and forming a paper interval formed variably longer by the fourth setting step. 13. The image forming apparatus according to claim 12, wherein a speed detection pattern is detected a plurality of times, and a moving speed average value calculated by the calculation step based on the detection result is processed as a moving speed value of the intermediate transfer body. Control method. 19. The control method for an image forming apparatus according to claim 18, wherein said environmental condition detecting step detects humidity or temperature. 20. The method according to claim 5, wherein the control step includes variably setting a paper interval length of the recording medium to be longer than a normal paper interval when the intermediate transfer body moving speed has changed by a predetermined value or more from the previous measurement. A setting step, detecting a speed detection pattern formed between sheets variably set longer in the fifth setting step a plurality of times, and calculating a moving speed average value calculated by the calculation step based on the detection result. 13. The method according to claim 12, wherein the processing is performed as a moving speed value of the intermediate transfer body. 21. The drive unit includes a drive roller, and the control step controls a drive state of the drive roller based on a calculation result of the calculation unit to control a transport speed of the intermediate transfer body. 17. The method according to claim 17,
21. The method for controlling an image forming apparatus according to any one of claims 18 and 20. 22. The image forming apparatus according to claim 12, wherein the intermediate transfer body is transported in a plane along a plurality of image stations and passes therethrough to form an image of each color.
22. The method for controlling an image forming apparatus according to any one of 8 and 21.